1. Field of the Invention
The present invention relates to computer-based information storage systems. More particularly, the present invention relates to systems and methods for synchronizing firmware resident on redundant controllers in a storage system, e.g., a RAID (Redundant Array of Independent Disks) array storage assembly.
2. Background of the Invention
The increased importance of information technology in business processes has fostered increased demands for data storage systems that combine the features of high storage capacity, high reliability, efficient scalabilty, and cost-effectiveness. Early computer systems relied heavily on direct-attached storage (DAS) systems consisting of one or more disk drives coupled to a system bus. DAS systems were not well adapted to satisfy these demands. More recently, storage area network (SAN) technologies have been implemented. SAN architectures permit organizations to uncouple application servers from data servers to provide storage systems with greater capacity, higher reliability, and higher availability.
SAN systems have implemented RAID (Redundant Arrays of Inexpensive Disks) techniques to enhanced data storage reliability. In addition, SAN systems may implement redundant components such as power supplies, cooling modules, disk devices, temperature sensors, audible and/or visible alarms, and RAID and other controllers to increase system reliability. If a component fails, then the redundant component assumes the functions of the failed component so the storage system can continue operating while the failed component is repaired or replaced.
In operation, remote computing devices may access a storage sub-system through a server that communicates with the storage sub-system. The term file system refers to the logical structures and software routines, usually closely tied to the operating system software, that are used to control access to storage in the system. File systems implement a mapping data structure that associates addresses used by application software to addresses used by the underlying storage layers. While early file systems addressed the storage using physical information about the hard disk(s), existing file systems address logical units (LUNs) that may comprise a single drive, a portion of a drive, or more than one drive.
Storage systems, including SAN file systems retrieve information from the storage media by issuing commands to a disk controller(s), typically through a network connection. A disk controller is a collection of hardware and software routines that translate the file system commands expressed in logical terms into hardware-specific commands expressed in a protocol understood by the physical drives. The disk controller may address the disks physically, however, more commonly a controller addresses logical block addresses (LBAs). The disk drives include a controller that maps the LBA requests into hardware-specific commands that identify a particular physical location on a storage media that is to be accessed.
In many SAN systems, data storage devices (e.g., disk drives) are connected to redundant disk controllers by at least one high-speed data communication link, e.g., a Fibre Channel Arbitrated Loop (FCAL), to provide a network of interconnected storage devices. To function effectively as redundant controllers, the disk controllers must run the same version of firmware on their respective processors. Accordingly, there is a need in the art for systems and methods to ensure that redundant disk controllers are running the same version of firmware in their respective processors.